In today's mobile society, safety and security of individuals whether in the home, in the workplace, or when traveling through a remote location is a primary concern. The universal nature of this concern is exhibited by the fact that 95% of all households list security as their primary reason for purchasing a cellular telephone. However, the lack of global cellular network coverage and frequent service reliability problems inherent in cellular communications make a cell phone a less than ideal personal safety device for individuals that are at high risk of injury and are frequently out of range of reliable cellular phone service, such as hikers, hunters, boaters, remote workers and travelers to high risk regions. Additionally, cellular phones provide a less than ideal means of notifying rescue authorities of an emergency in situations wherein a user is at a high risk of incapacitation, such as automobile crashes, home break-ins or fires, and in situations where a high degree of third party monitoring is necessary, such as in the monitoring of hazardous material carriers.
There are currently a few devices and systems in the consumer market that attempt to address these concerns. However, those devices and systems have significant deficiencies.
For the last several years, the alarm reporting industry has provided security services to both private residences and small businesses using electronic control panels and central station monitoring equipment that communicates using Dual Tone Multiple Frequency (DTMF) modulation which is supported by local Public Switched Telephone Networks (PSTN). In receiving reports of real-time alarm events, DTMF receiving units at the central monitoring stations perform handshakes and decipher identification strings of data sent by the alarm control panels in order to determine the identification of the customer and the specific nature of the alarm. The two-way capacity of the PSTN also facilitates the ability of the central station operators to send confirmation return requests back to the alarm control units.
In many cases, the providers of electronic security services provide a secondary fully redundant wireless backup communications method that transports the alarm reporting DTMF strings to the central station in the event the local telephone hard-wired services or primary electrical power sources were either deliberately or accidentally disrupted. The wireless system(s) of choice used to communicate the backup alarms have been local cellular communication services. This type of redundant security service brings with it the added costs for both the equipment and monthly cellular service fees. In addition, the availability and reliability of these wireless backup services is totally dependent on the local wireless carrier's actual service coverage range. Due to high volume congestion and the well known dropped calls experienced at peak usage times, wireless cellular communication is not dependable enough for alarm reporting, and therefore does not provide a reliable backup option.
Today, for the most part, alarm reporting service providers continue to support DTMF communications services for subscribers that have older DTMF-only equipment. However, with the objective of obtaining a higher level of efficiency, a newer communications protocol for alarm reporting has been widely accepted and implemented by security industry leaders. That method, referred to as the “Ademco Contact ID” protocol, uses a relatively low-speed but very dependable end-to-end modem communications routine. This format contains a four-digit account number, a three-digit alarm code, a pin status, a two digit area number and a three digit zone or user number. The Ademco Contact-ID format can be depicted as follows:                AAAA P CCC XX ZZZwhere AAAA is the account number, P is the pin status (alarm or restore), CCC is the alarm code (which is pre-defined by Ademco), XX is the area number and ZZZ is the zone or user number. The total number of characters required for a complete alarm reporting session, including delimiters, is seventeen.        
In addition to home security alarm reporting, there have been efforts to develop a reliable Automatic Crash Notification (ACN) system to enhance the response time of rescue personnel in responding to vehicular crashes. Some vehicle manufacturers have developed ACN systems that are activated by the deployment of a vehicle's air bag system. Use of airbag deployment to activate ACN systems is preferred because air bag systems are virtually standard in new car models. The major system components of the air bag systems are the crash sensors, air bag control system, inflator and the air bag. The air bag control system generally includes control modules that provide direct access via external connectors to continuous real time system data, including air bag deployment alerts which can be used to activate an ACN system.
An example of such an ACN system currently on the market is the OnStar™ in-vehicle safety and communications system offered by General Motors Corporation as an option on select vehicles. The OnStar™ system uses local wireless cellular services to report notice of a crash to an OnStar™ call center system, which then makes emergency information available to a local 911 operator so that appropriate life-saving personnel and equipment can be dispatched to crash scenes. In addition to the aforementioned reliability problems inherent in the cellular services used by OnStar™, there are also coverage availability concerns, particularly in rural areas where about sixty percent of the nation's automotive fatalities occur. Traffic safety and emergency medical experts agree that an ACN system is much more critical in rural areas, where there may not be a passerby to report a crash for a long time after the crash, and where there are fewer local hospitals equipped to treat the kinds of injuries sustained in severe crashes.
Hence, there is a need for a low-cost ACN system that is activated by the deployment of the vehicle's air bag system and which is capable of communicating a crash alert to rescue personnel over a reliable, widely available wireless communication system.
Some existing ACN systems make use of the Global Positioning System (GPS). GPS, which is comprised of a constellation of over fifty satellites, and provides the only truly global satellite navigation system. GPS can be used to determine one's precise location and to provide a highly accurate time reference almost anywhere on Earth or in Earth orbit. The accuracy of the GPS is about 5 meters (16 feet) as of 2005, and has steadily improved over the last several years. Using differential GPS and other error-correcting techniques, its accuracy can be improved to about 1 centimeter (0.4 inches) over short distances. Although the GPS satellite system was designed by and is controlled by the United States Department of Defense primarily for military purposes, it can be used by anyone, free of charge. In the realm of global emergency systems, use of GPS is particularly important in situations where the location of a person needing assistance is not fixed or known.
While GPS can be used to obtain the coordinates of an individual's location, it does not provide a means to transmit and process emergency alerts. This need is addressed by Cospas-Sarsat. Cospas-Sarsat is an international search and rescue system that uses satellites to detect and locate emergency beacons carried by ships, aircrafts or individuals. As shown in FIG. 1, this system 10 consists of a network of satellites 2, ground stations which are referred to as Local User Terminals (LUT) 3, mission control centers 4 and rescue coordination centers 5. Each satellite 2 in the Cospas-Sarsat system can detect and locate alert signals transmitted from 406 MHz beacons 1 that are in the satellite's reception footprint. The satellite 2 then relays the alert signal to a LUT 3 when the satellite 2 is within view of the LUT 3. The Cospas-Sarsat system 10 also allows for the encoding of position data in the transmitted 406 MHz message, thereby providing for quasi-real time alerting with position information. This position data can be obtained from a GPS receiver connected to the emergency beacon transmitter and encoded into the message string transmitted by the beacon.
Since its deployment, the Cospas-Sarsat system has provided a tremendous resource for protecting the lives of aviators and mariners that was unthinkable prior to the space age. Prior to 1995, there were only two types of beacons approved for use within the Cospas-Sarsat system: (1) Emergency Locator Transmitters (ELT) for aircraft and (2) Emergency Position Indicating Radio Beacons (EPIRB) for maritime vessels. In 1995, the system was expanded to allow testing of personal locator beacons (PLBs) in the harsh terrain of the State of Alaska. In 2003, as a result of the success of the test in Alaska, the National Oceanographic and Atmospheric Administration (NOAA) approved the use of PLBs in all of the United States for private and personal use. Since then, many lives and millions of taxpayer dollars have been saved due to search and rescue operations assisted by the use of this satellite-based technology.
The Air Force Rescue Coordination Center (AFRCC) is the government agency responsible for handling distress calls received over Cospas-Sarsat. Now that Cospas-Sarsat is available for private and personal use, the AFRCC simply does not have the means to handle the anticipated workload generated by the thousands of consumer devices that are expected to utilize the system as the primary means of communicating emergency alerts. As a result of the lack of government resources available to support private use of Cospas-Sarsat, very little business development has taken place to take advantage of the availability of Cospas-Sarsat.
Therefore, a system is needed that can harness the global reliability of the GPS and Cospas-Sarsat systems to facilitate the transmission of personal distress signals from consumer devices, such as home alarm systems and ACN systems, without overwhelming the infrastructure that currently handles distress alert signals.
Also, a wireless alarm communication system is needed that is globally ubiquitous and not prone to service outages due to high volume of use, power failures, or natural disaster, and which is capable of communication using industry standard protocols, such as the Ademco Contact ID standard, which are compatible with existing alarm monitoring infrastructures.